gigabyte 890gpa-ud3h memory configuration

[wanner]

My system specs are:
gigabyte 890gpa-ud3h
phenom II X4 945 3.0GHz
Corsair 4GB (KIT) 1600MHz XMS3 (CMX4GX3M2A1600C7)

According to specs the memory should run 1600MHz at 7-8-7-20.
However when i let BIOS automatically adjust the memory settings it picks 1333MHz at 9-9-9-24

This screengrab from CPU-Z shows the settings when on auto in BIOS


Here are the timingtables from CPU-Z


Q1: I read that my memories are rated for a Core i5/i7 processor and not AMD, is that why it picks 1333MHz when on auto?

I decided to try to manually adjust the settings according to the memory specs and it seems to be working fine, the computer boots but i havent had any chance to stresstest it to see if its stable.  
Q2: However, in order to run the memory at 1600MHz I have to adjust the voltage to 1.65v which is shown in red in bios indicating an overclock. Is this something i should be worried about?

Image showing memory settings after manual adjustment


Q3: As you can see the FSB:DRAM changed from 3:10 to 1:4, is this something i need to worry about?

Would really appreciate some help with this!

[Dark Mantis]

This is a major problem with this CPU/motherboard chipset at present. If you do a search of the forum you will see what I mean. My buddy absic is actually in the midst of doing a series of tests to try to determine the underlying root problem here. So keep an eye on this thread:
http://forum.giga-byte.co.uk/index.php/topic,2379.0.html

[wanner]

Thanks for your reply, however, it says: "The main area of concern is the inability to run RAM at stated speeds above 1333 Mhz  if all of the memory slots are filled on the motherboard. I myself have faced this on my own PC and am using this as a comparison set-up as I know that this is now working OK."

I am not using all of the memory slots, only 2. Which reminds me, should i be using different memory slots when running 1333MHz and when running 1600MHz? If so, which slots should i be using for 1600MHz?

[absic]

Hi,

If you are using 2 sticks of ram you should be using them in either the white or the blue slots. Try setting them to Unganged Mode.

Be careful of CPU-Z as I have noticed in my current phase of testing that there is a problem with the way it is reporting voltages, timings etc. For a more accurate picture try using CPUID HW Monitor Download from here: http://www.cpuid.com/softwares/hwmonitor.html ) or Gigabyte's EasyTune 6

I read that my memories are rated for a Core i5/i7 processor and not AMD, is that why it picks 1333MHz when on auto?

The answer to that question is no. It is because the AMD CPU Memory controller is I believe set to not run above 1333 Mhz. When it default it will automatically go to these settings for greater system stability.

As Dark Mantis mentioned in his earlier post, I am carrying out some research into this problem as we speak. So keep an eye on that thread as I will be posting updates and pictures as I go through the testing process.

[wanner]

Hi,

If you are using 2 sticks of ram you should be using them in either the white or the blue slots. Try setting them to Unganged Mode.

Be careful of CPU-Z as I have noticed in my current phase of testing that there is a problem with the way it is reporting voltages, timings etc. For a more accurate picture try using CPUID HW Monitor Download from here: http://www.cpuid.com/softwares/hwmonitor.html ) or Gigabyte's EasyTune 6

I read that my memories are rated for a Core i5/i7 processor and not AMD, is that why it picks 1333MHz when on auto?

The answer to that question is no. It is because the AMD CPU Memory controller is I believe set to not run above 1333 Mhz. When it default it will automatically go to these settings for greater system stability.

As Dark Mantis mentioned in his earlier post, I am carrying out some research into this problem as we speak. So keep an eye on that thread as I will be posting updates and pictures as I go through the testing process.

Ah, thanks for your answer. It sounds like perhaps it would be a good idea to run at 1333 MHz then? I will keep an eye on your thread.

[absic]

Yes, sorry but there really isn't much else to do, just at the moment.

I am hoping to expand my tests to cover one of the 8 series motherboards, such as you have, but am relying on the generosity of others to allow me to do that.

I anticipate posting my first update to the testing thread, later today and I hope that you find it informative as well as hopefully answering your questions.

If you think that there is something I am missing in my tests or if there is an area you would like me to look at, please feel free to send me a PM and I will do what I can to help.

[wanner]

Yes, sorry but there really isn't much else to do, just at the moment.

However, if my computer runs stable with the memories at 1600 MHz and 7-8-7-20 everything should be fine? Or should I be concerned that the voltage is shown in red when setting it to 1.65v?

Another question, I ran the memories at 1600MHz 1.65v with timings 7-8-7-20 for a while and it seemed to work fine, but then when i put it back to auto in BIOS it choose to continue running at 1600MHz and 1.65v (1.65v not showing in red anymore) instead of 1333MHz 1.5v which it had previously chosen when on auto. The timings went back to 9-9-9-24 though. How come the auto settings changed? Now im not sure if I should keep it at auto and running at 1600MHz 1.65v (which atm is auto) or if I should lower it to 1333MHz 1.5v.

Thanks

[absic]

Hi,

Not sure of how BIOS works on the newer motherboards but, if it is now running at 1600Mhz@1.65V and everything is fine, then leave it alone.

Even if the voltage is shown in red when set at 1.65V in BIOS this is to show that you have moved away from what BIOS thinks is normal. The fact that the memory is designed to run at 1.65V means that you are quite safe.

Hope this helps

[Dark Mantis]

I would agree with absic and I would have got in first if the phone hadn't rung! You should just continue with your current settings.

[wanner]

I will try running at 1600MHz@1.65v some more to see if its really stable. I only tested it in windows, no heavy activity. I just find it strange that it sometimes picks 1333MHz@1.5v and sometimes 1600MHz@1.65v as normal.

Anyone got an answer to my previous question wether it affects performance in any way that FSB:DRAM changed from 3:10 to 1:4 when changing to 1600MHz@1.65v.

Really appreciate your answers!

[Dark Mantis]

Basically all it 's aying is that it's dropped the frontside bus a little and kept the ram the same to get those settings. FSB:DRAM 3:10 to 2.5:10

[phayes]

I am not using all of the memory slots, only 2. Which reminds me, should i be using different memory slots when running 1333MHz and when running 1600MHz? If so, which slots should i be using for 1600MHz?

Not sure if it's at all relevant for 1600MHz but it says in the “(Note 2)”s on pages 8 and 12 of the manual that “to reach 1866MHz or above, you must install two memory modules and install them in the DDR3_3 and DDR3_4 memory sockets”

[Dark Mantis]

This is what absic is trying to determine by doing these tests now. But as far as your question goes you need to use slots 3&4 for any of the faster memory modules. But that limits you to two modules only.